Process for making composite materials



Patented Oct. 29, 1940 i i r I y 4 I UNITED STATES PATENT OFFICE 2,219,447 raocnss son MAKING comosrrn MATERIALS .Frazier Groif, Lakewood, Ohio, assignor, by mesne assignments, to Union Carbide and Carbon Corpotation, a corporation of New York No Drawing. Original-application July 15, 1931, Serial No. 551,061. Divided and this application June 19, 193 Serial No. 86,079-

3 Claims. (Cl. 15l 2) The inventionrelates to the production of arbe converted to the final infusible state difler.

, ticles, or stock from whichto make finished artiwidely from the Optimum o d t o s 01 8 cles, by combining a plurality of types of resinous vinyl resins. materials, whereby one of the resinous materials T e p nt t O o ds minimizes can be caused to supply qualities in which anthese difliculties and has for its principal object other is deficient, all as more particularly herethe p o o o & P e fo ll! composite inafter described, materials including thermo-setting resins and Thermo-setting resins, for example phenolvinyl es I methylene, phenol-aldehyde, phenol-furfural, have found by e e e a on t at an b- 1n urea formaldehyde and glyptal resins, can be l st composed o i u e a o so 10 formed at moderate temperatures, but higher herm -set s resin can be P d t ntemperatures render them permanently immoteg b o e surface portion to which Vinyl bile and infusible. Such resins are extensively res W ll adhere when it is molded thereagainst.

used as molding plastics and possess desirable s di ve y a e abled me to attain the obin properties, such as insolubility, resistance toheat, loci: of the invention and toprepare composite mechanical strength and rigidity; but these art c es 'by ol a es u der conditions resins also possesscertaln qualities which'detract best uited to its p p es e resultant comirom theirusefulness. For example, some ofposite combines the desirable properties ofboth these resins are difiicult to prepare in light colors aterials.

. or their colors tend to be unstable toward light; The following examples are'illustrative oi the others are characterized by a low degree of elecinvention:

trical arc resistance; and those prepared from I. A plurality of sheets of paper were impregphenols usually retain a .phenolic odor. Still sted with pote a y reactive Phenolic p st c other thermo-setting resins are diflicult to mold and placed together between unimpregnated and the quality of the shaped article varies with sheets so that the latter formed the top and the molding conditions. bottom layers of the assembly. The assembly Vinyl resins, that is, resins made by polymerizwas then-molded at a temperature of about 150 ing certain vinyl compounds are tough, odorless, C; to 170 C. until the thermo-setting resin was permanently thermoplastic, easily 'moldable and entirely converted to the. infusible state. The n chemically inert. They are readily prepared in 1 resulting. product was a laminated press board stable colors of any shade, and possess a high having an niu e nter o tegrally Joined to degree of electrical arc resistance, but the heat [absorbing su of untreated p p T resistance of the vinyl resins is usually inferior press board was th n dipp d in a 0% solution of to that of the thermo-setting resins. vinyl resin in acetonejthe solvent was evaporated, Thus, it is immediately apparent that if the and the board was molded at about 130 to 140 35 desirable qualities of each type of resin could be to f rm a mposi materi h vin n lniusible combined in a composite material, the latter thermo-s'etting resin interior with a surface of would be superior for many purposes to any vinyl resin- Th vi yl in lu ion m y be product which would be made from either type colored with lakes, dyes or pigments. 40 of resin alone; But on attempting to mold the If a thicker surface of vinyl resin is desired, 0

.two types of resins together to form a comthe resin may be applied in the form of preposite combining a surface oi vinyl resin with a formed sheet, or as powder. This can be done' core or base of an infusible thermo-setting resin, with or without the application of a solution of the unexpected fact was discovered that vinyl vinyl resin to the original press board. Instead 5 resins molded nst cured or. infusible thermoof using sheets of paper which are impregnated setting resins do not adhere thereto. In fact this with the thermo-setting resin, untreated paper lack of adhesion is so marked that vinyl resins may be used and the thermo-setting resin may m y be molded in matrices formed from thermobe distributed between the layers of paper. setting resins, which have been converted to the II. A piece of a fibrous material, such as pulp infusible state, in lleu of metal molds. Also, difboard, was treated with a solution of a poteno ficulties are encountered in molding vinyl resins tially reactive phenolic resin. The solvent was against thermo-setting resins which are not cured evaporated and the board was baked until the but which are in the potentially reactive state, thermo-setting resin was partially converted to for the reason that the temperature and time the infuslble state; Sheets or paper treated on required to cause the thermo-setting resins to one surface with a potentially reactive phenolic 55 resin were molded against the outer surfaces of the impregnated board and the resin was con-. verted,,to the infusible state. The product was alaminated article having an infusible interior, integrally joined to absorbing surfaces. This laminated paper and pulp board base was then surfaced with a vinyl resin by the application of a vinyl resin solution or molding composition, or

111.. mixture of a phenolic resin molding composition and a vinyl resin molding composition containing parts of the phenolic resin composition and 50 parts of the vinyl resin composition was dusted over paper impregnated with a potentially reactive phenolic resin. This assembly was in turn covered with vinyl resin sheet stock or moldingcomposition and molded at 150 C. to form a phenolic resin composite surfaced with a vinyl resin composition. I

IV. A piece of felt was impregnated with a solution of a phenolic resin and rosin containing about 2 parts of rosin to 3 parts of the phenolic resin. The impregnated material was dried and baked'to cure the phenolic resin. This treatment produced an impregnated base which was soft and which remained fibrous, but which was stiffer and stronger than the original material.

1oins'substance which does notinciude any acid- The phenolic resin was diluted with the rosin, hence, it was possible to create a bond between the impregnated base and a-vinyi resin. A vinyl resin molding composition was then molded against the upper and lower surfaces of the 1mpregnated material to form a vinyl resin surfaced composite. This type-ofprocess may be advantageously applied to the formation of articles having a softer interior with a hard exterior of a vinyl resin composition. l

v V. .A molding composition including both thermo-setting and vinyl resins was prepared as follows: a quantity of wood fiour was treated with a solution containing the reaction product of 2 mole of formaldehyde and 1 mol of urea. This mixturewasdriedandbakedinanovenatfl' to 100 C. to cure the resin. Three hundred parts ofthisproductwasmixedwith mpartsofvinyl resin, .1 part'of carnaubawax and lpart of calcium stearate. The mixture was rolled for about five minutes on heated diiferential rolls to thoroughly incorporatethe ingredients. The product after being rolled was ground and used as a general molding composition.

'Manytypes of vinylresins maybeusedt'o-form mynew material. A preferred vinyl resin is-a product resulting from the polymerisation of a mixture of %to of vinyl chloride and 6% moors of vinyl acetate. and which-is 80% soluble in 001d (20' to 30' C.) toluene. I

prefer to insure complete stability of' the vinyl resinbyincorporatingtherewithabasicstabilis- 'ing thewhole under heat'andpressure to 'theoompositeartiele.

forming or oxidizing groups in its composition,

such as alkaline earth metal salts of the fatty Many modifications of my process are possible,v

and are included within the invention as defined by the appended claims. This application is a division of my copendingapplication Serial No. 551,061 filed July 15, .1931. I

I claim:

1. Process for making composite materials including phenolic resin requiring a cure at temperatures of at least 150 C. to 170C. and vinyl resin including a polymerized vinyl ester, said vinyl resin having inferior heat resistance at said temperatures and being normally non-adherent to said phenolic resin when the phenolic resin is in the infusible state, which includes the steps of forming an object comprising such a phenolic resin, and at least one surface of fibrous, absorbent material to which vinyl resin will adhere; converting the phenolic resin into the in-' fusible state by the application of heat at temperatures of at least 150 C. to .170.; and subsequently applying said vinyl resin to said surface and consolidating the whole under heat and pres-- sure toform the composite article.

2. Process for making composite materials including vinyl resins and phenolic resins, the lat-v ter requiring a cureat temperatures of at least 150 C. to 170 C., and to which said vinyl resins will not ordinarily adhere when the phenolic resin is in the infusible state. which includes the stepsof forming an object comprising such a phenolic resin, and at least one surface of fibrous,

absorbent material to which vinyl resin will adhere: converting the phenolic resin into the infusible state by the application of heat'at temperatures of at least 150 C. to 0.; andsubsequently applying a vinyl resin substantially identical with a resin formed by conjoint polymerlsstion of a vinyl halide with a vinyl ester ofan aliphatic acid to said surface and consolidating the whole under heat and pressure to form the compositearticle.

I 3. Process. for making composite materials including vinyl resins and phenolic resins, the latter requiring a cure at temperatures of at least C. to C.', and to which said vinyl resins will not ordinarily adhere when the phenolic resin is in the infusible-stlite, which includes the steps of forming a laminated object comprising a plurality 'offibrous laminations impregnatedlwith such a, phenolic resin, and atleast one surface of fibrous, absorbent material to which vinyl resin will adhere; converting the phenol resin into the infusible state by the application of heat at temperatures of at least 150" C. to 170 0.; and subsequently applying a vinyl resin substantially identical with a. resin formed by conjoint polymerisation of.a.mixture of about 70% to about 05% of vinyl chloride with about 80% to'about 0% vinyl acetate to said surface and'oonsolidatform I (more. 

